Medium Energy Ion Scattering Studies of Thin Films

本项目研究与技术相关的薄膜的结构、组成、生长和反应性等基本问题。该研究探索了超薄氧化物在临界厚度1-10纳米范围内的薄膜和界面行为。计划包括生长和分析在Si， Ge和SiC上生长的薄膜。所采用的主要技术是高分辨率介质能量离子散射（MEIS），能够准确测定成分作为深度的函数，在某些情况下，还可以精确测定结构。MEIS实验将辅以红外吸收光谱、扫描隧道显微镜、原子力显微镜和光电子能谱。有些方面将与贝尔实验室和其他地方的工业科学家合作完成。该项目还涉及离子表面相互作用的基础研究，特别是当薄膜厚度降至1纳米以下时，电子激发过程对离子散射光谱的影响。目的是提供对表面和超薄膜的高分辨率深度剖面的基本理解。这项工作将在理论家的密切合作下完成。这项工作的更广泛的技术影响源于对薄膜生长的微观理解和新的实验和理论工具的发展。以原子概念为基础的概念理解将达到一个新的水平，这将有助于电子学的继续发展。该项目涉及与技术相关的电子材料科学和凝聚态物理领域的基础研究问题。该项目的一个重要特点是非常重视教育，并将研究与教育相结合。该研究项目为使用先进科学设备的实践经验提供了极好的机会。综合资源，包括实验和理论方法，为参与高度跨学科前沿研究的博士后、研究生和本科生的教育和培训提供了特殊的机会。所获得的信息的直接和视觉导向的性质有助于将表面和材料科学的兴奋传达给本科生以及初高中学生

This project addresses fundamental issues of structure, composition, growth and reactivity on tech-nologically relevant thin films. The research explores film and interface behavior of ultrathin oxides in the critical 1-10 nm thickness range. Plans include growth and analysis of films grown on Si, Ge and SiC. The primary technique employed is high-resolution medium energy ion scat-tering (MEIS), enabling accurate determination of composition as a function of depth, and, in some cases, precise structure determinations. The MEIS experiments will be complemented with infrared absorption spectroscopy, scanning tunneling microscopy, atomic force microscopy, and photoelectron spectroscopy. Some aspects will be done in collaboration with industrial scientists at Bell Labs and elsewhere. The project also addresses fundamental studies of ion-surface inter-actions, specifically the effect of electronic excitation processes on ion scattering spectra as the film thickness drops below one nanometer. The aim is to provide fundamental understanding of high-resolution depth profiling of surfaces and ultrathin films. This work will be done in close collaboration with theorists. The broader technological impact of this work results from devel-opment of a microscopic understanding of thin film growth and of new experimental and theo-retical tools. A new level of conceptual understanding, based on atomic concepts, is expected to emerge which will aid in the continued development of electronics. %%% The project addresses fundamental research issues in areas of electronic materials science and condensed matter physics having technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. The research program provides excellent opportunities for hands-on experience in the use of sophisticated sci-entific equipment. The combined resources, including experimental and theoretical methods, provide special opportunities for education and training of post doctoral associates, graduate and undergraduate students involved in highly interdisciplinary forefront research. The direct and visually oriented nature of the information obtained facilitates communication of the excitement of surface and materials science to undergraduates as well as middle and high school students.***